(a) Field of the Invention
Embodiments of the present invention relate generally to flat panel displays. More specifically, embodiments of the present invention relate to a liquid crystal display and a method for manufacturing the same.
(b) Description of the Related Art
Liquid crystal displays are one flat panel display technology that has found wide acceptance. Typical liquid crystal displays include two sheets of display panels on which electric field generating electrodes, such as pixel electrodes and common electrodes, are formed. A liquid crystal layer is inserted between the display panels. Liquid crystal displays generate an electric field in the liquid crystal layer by applying a voltage to the electric field generating electrode, determining the directions of the liquid crystal molecules via the resulting electric field, and displaying an image by controlling polarization of incident light.
A predetermined cell gap is preferably maintained between the two display panels, and for this, active spacers can be used. Bead spacers and column spacers can be used as the active spacer.
Bead spacers are advantageous in that they can be produced by s simple process and are thus relatively easy to manufacture. However, bead spacers often float within liquid crystal, and thus move with the liquid crystal during injection. If the bead spacers are moved sufficiently far, they may press against an alignment layer, causing undesirable light leakage. Alternatively (though somewhat rarely), the column spacers may instead be formed by photolithography, such that they are fixed at desired positions. However, these column spacers have smaller elastic strength as well as smear characteristics, such that the panel may be stained due to collapse of the column spacers or the lower layer when large pressure is applied to the liquid crystal display.
Everyday use, accidental impacts, and simple atmospheric pressure can result in forces applied to liquid crystal displays. These forces can be vertical loads, or two- or three-dimensional loads with both vertical and horizontal components.
When a sufficiently large vertical (i.e., normal to the face of the display screen) load is applied, the column spacers may be plastically deformed, and may fail to recover their original shape after the load is removed. This may result in permanent depressions in the display, where the liquid crystal layer is thinner than in other areas, in turn resulting in local luminance differences.
When a three-dimensional load is applied, the column spacers may slide, moving to an active region. When this happens, the alignment layer of the active region may be damaged and/or stained.
Further, when a three-dimensional load is applied, the column spacers may fail to return to the initial positions and cell gaps may be changed by the movement of the column spacers, even if the alignment layer is not damaged. Stains may be seen in the panel, as regions with different cell gaps display different luminances.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and thus may contain information not in the prior art.